Phase equilibrium modeling in biodiesel production by reactive distillation

The phase equilibrium of interest in biodiesel production by reactive distillation was modeled. Mixtures were composed of the main components found in esterification and transesterification reactions. The pure component thermophysical properties of acylglycerols were predicted and evaluated by comparison with available experimental data. Databanks of vapour-liquid equilibrium, liquid-liquid equilibrium and vapour-liquid-liquid equilibrium experimental data were created for the mixtures in the biodiesel production process. The experimental data evaluated were then used to develop a rigorous thermodynamic modeling using the NRTL model. Three binary interaction parameter sets were regressed. Two NRTL parameter sets can be used to simulate the catalytic distillation column of interest in the production of biodiesel from residual oil and fats by a solid acid catalyzed process. The third parameter set is useful to simulate the reactive distillation column applicable in the biodiesel production by the homogeneous alkali catalyzed process. The phase behavior of the mixtures studied was correctly described by the proposed modeling for pressures up to 750 kPa. The proposed phase equilibrium modeling was then validated against experimental results reported for biodiesel production by reactive distillation.